Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect X20 connector from the PCB
Disconnect the lead to the overheat stat
Disconnect the lead to the overheat stat
Measurement:
Measure the continuity of the overheat stat harness.
Expected resistance is short circuit, zero ohms.
Expected resistance is short circuit, zero ohms.
Isolate as per TOPs P4
and refit as necessary